#2 - I’d work under that assumption, just use netlify-honeypot - if still concerned you could easily do a plain HTML file test to confirm that it sees and removes netlify-honeypot
#3 - I see no mention of netlify dev in the forms documentation, and no mention of forms in the netlify dev documentation, my assumption would be that you cannot test forms with netlify dev and that seems to be confirmed by this post
#4 - You probably have already, but when submitting the form you could look at the request in your network tab and confirm what values are being submitted.